Electrical connector



United States V PatentO" 3,328,745 ELECTRICAL CONNECTOR Clarence Leonard Paullus, Carlisle,Pa.,' assignor to AMP Incorporated, Harrisburg, Pa. Filed Apr. 7, 1965, Ser. No. 446,352 Claims. (Cl. 339--61) tacts which does not depend on the use of retention springs or other devices on the contacts or in the connector cavities. A further object is to provide a connector which permits insertion and removal of the individual contact terminals after they have been secured to the ends of wires. 1

These and other objects of the invention are achieved in a preferred embodiment thereof in which the connector comprises an insulating block having hard noncompressible end sections and a soft compressible center ,section. Means are provided for moving the end sections relatively towards each other from an extended position to a proximate position, the compressible center section being compressed and shortened during such movement of the end sections. A plurality of contact-receiving cavities extend through the block, each such cavity extending from one of the end sections, through the center section and through the other one of the end sections. Each cavity has first and third portions in the one end section and the other end section respectively, and a second portion in the compressible center section. The second portion of each cavity extends obliquely with respect to the first and third portions of the cavity so that the cavity has a predetermined degree of tortuosity when the sections are in their extended positions with respect to each other. The length and diameter of the contact terminals used in the ;connector is such (relative to the diameter, length, and degree of tortuosity of the cavities) that the individual contact terminals can be inserted into the cavities when the end sections are in their extended position..When the end sections are moved-towards each other to their proximate positions, the degree of tortuosity'i'n the individual cavities is increased, that is, the curve or curves in the cavity are made more abrupt, to the extent that the contact terminals cannot be removed from the connector. t

In the drawing:

FIGURE 1 is a half section side View of a connector assembly in accordance with the invention;

FIGURE 2 is a fragmentary-sectional side view on an enlarged scale of an individual terminal-receiving cavity of the connector of FIGURE 1, this view showing the relative positions of the parts when the end sections of the insert assembly are in their extended positions relative to each other; and

FIGURE 3 is a view similar to FIGURE 2 but showing the profile of the cavity when the end sections of the insert assembly are in their proximate position, this view illustrating the manner in which the individual contact terminals are retained in the connector.

FIGURE 1 shows a simplified'form of electrical connector assembly incorporating the instant invention and comprising a socket portion 2 and a plug portion 3. Since the plug portion and the socket portionare similar to each other in essential respects, and since each part of the connector assembly incorporates a contact retention 3,328,745 Patented June 27, 1967 ice system in accordance with the invention, only the socket portion 2 will be described in detail.

The socket 2 comprises a conventional cylindrical metallic shell member 4 having an insert block assembly therein comprising three individual sections 6, 8, 10

between the washer 17 and one side of the flange. A

helical cam track 27 on the internal surface of ring 13 is adapted to receive a pin 21 on a projecting hood 23 of the plug half 3. The two halves of the connector can thus be coupled by moving the pin 21 relatively into the open end of track 27 and rotating the locking ring.

The sections 6 and 10 of the insert assembly are advantageously of a firm insulating material such as an epoxy resin or diallyl phthalate while the center section 8 is of a soft and compressible insulating material such as a suitable silicone or polyurethane rubber. If a sealed connector is desired, the interfaces 5 and 7 between the center section 8 and the end sections may be'bonded by suitable adhesive, for example, a methyl silicone adhesive such as A-4000 manufactured by the Dow Chemical Company. Additionally, insert section 6 may be bonded around its periphery to the internal surface of the shell 4 although, for reasons which will be explained more fully below, the insert sections 8 and 10 should not be bonded to the shell.

6, a portion 14 in the center insert section 8, and a portion 16 in the end insert portion 10. At its right-hand end, -as viewed in FIGURE 2, the cavity portion 12 is provided with a constriction formed by a conical surface 18 and a pair of reduced diameter portions 20, 22. This cavity has a conical entrance portion 24 on its right-hand side to facilitate guiding of the pins 9 into the sockets 26;

The portions 10 and 12 of each individual cavity are in parallel oifset relationship with respect to each other,

-in other words, the axes of these sections extend parallel to each other but are slightly offset as is apparent from FIGURE 2. The portion 14 of the cavity extends obliquely with respect to the axes of the sections 12, 16 and this portion of the cavity connects the two parallel portions 12, 16 so that the profile of the cavity is slightly tortuous.

The socket portion 2 of the connector is adapted to have mounted therein a plurality of contact socket terminals, each contact comprising a socket portion 26 into which the pin portion9 of a mating contact can be 111- serted, and a slightly enlarged end portion 28. It is understood that each socket is axially bored on its left-hand end and crimped, as shown at 29, onto the end of a wire 30. The diameter of the enlarged diameter end portion '28 of'the socket is substantially equal to and slightly :smaller than the diameter of the cavity and the length of the contact is such that it can be snaked through the cavity portions 14, 16 and around the curve or bend in the cavity until its forward end is moved against the shoulder 25 formed between the reduced diameter sections 20, 22.

The end section 10 of the insert assembly has radially extending ears 32 on its periphery which project through slots 34 in the shell 4, the length of these slots as measured in the direction of the connector axis 'being suflicient to permit limited rightward movement of the insert section 10 from the position of FIGURE 2 t the position of FIGURE 3. A nut 36 is threaded on the external surface of the shell 4 and rearwardly of the cars 32, the arrangement being such that upon tightening this nut against the ears, the insert section will be moved rightwardly and towards the insert section 6.

When the individual contacts are to be inserted into the cavities of the socket section 2, the nut 36 is backed away from the cars 32 until the compressible center section 8 of the insert assembly assumes its normal expanded condition (FIGURE 2). The contact terminals are then inserted as illustrated in FIGURE 2 until their ends abut the shoulders 25. The nut 36 is then tightened against the cars 32 to move the end sections 6, 10 to their proximate position with respect to each other. Such movement of the section 10 towards the section 6 results in a compression of the center section 8. The portion 14 of the cavity is effectively shortened as a result of such movement of the section 10 and the degree of tortuosity of the cavity is effectively increased as is apparent from the comparison of FIGURES 2 and 3. After such movement of the end section 10 and compression of the center section 8 of the insert assembly, it becomes impossible to remove the contacts from the cavities and they are effectively retained in the connector.

It should be added that when the center section 8 of the insert assembly is compressed, the portions 14 of the individual cavities will be at least partially filled, as shown in FIGURE 3, by the compressed insulating material of the center section, this insulating material being forced to flow inwardly of the cavities as a result of its axial (with relation to the connection axis) compression. It has been determined that only a limited amount of movement of the section 10 toward the section 6 is required to retain the contacts in the cavities if the cavity diameters and the contact diameters and lengths are judiciously selected. For example, where the socket contact has a length of about 0.500 inch and a diameter of about 0.070 inch, the section 8 of the insert assembly can have a thickness of about 0.100 inch and the offset or displacement of the center lines of the cavity portions 12, 16 can 'be of about 0.012 inch. With these approximate dimensions, the contact sockets can be snaked into the cavities with relative ease. When the nut 36 is tightened to cause a movement of about 0.060 inch, the degree of tortuosity of the individual cavities and the flow of the material of the section 8 into the cavities will be sufiicient to retain the contacts in their cavities.

The pin contacts are usually somewhat longer than the socket contacts in the connector, however, the added length of the pin contacts does not give rise to any insertion problems since the ends 9 of the pins are of a diameter smaller than the diameter of the socket ends 26 of the socket contacts. These pin contacts can, therefore, also be inserted with relative ease into the cavities.

It will be apparent that the principles of the invention can be applied to alternative forms of connectors and/ or cavities. For example, the means for moving the end section 10 of the insert assembly toward the section 6 can take the form of a nut threaded on the internal surface of the shell or a camming ring on the external surface of the shell. The tortuosity of the cavity need not be precisely as shown in the drawing with the cavity portions 12, 16 being offset and parallel to each other but can be achieved by merely having the center cavity portion 14 extending obliquely of the end cavity portions (i.e. the portions 12, 16 need not necessarily be parallel). The connector can be provided with suitable interface sealing gaskets and wire-sealing grommets (which would be mounted to the left of the section 10 as viewed in FIGURE 1).

Under some circumstances it might be desirable to provide interengaging means on the nut 36 and the cars 32. With such an arrangement, the disc 10 would be pulled rearwardly of the shell by the nut upon backing off the nut. One suitable interengaging means of this type would comprise an axially extending flange in the nut 36 and extending past the ears 32 with an inwardly directed lip on the end of the flange extending beyond the ends of the ears. An arrangement of this type would permit rotation of the nut relative to the shell and the lip would pull the ears (and the disc 10) rearwardly upon rearward movement of the nut.

Changes in construction will occur to those skilled in the are and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to bedefined in the following claims when viewed in their proper perspective against the prior art.

Iclaim:

1. An electrical connector comprising insulating block means having hard substantially non-compressible end sections and a soft compressible center section, a contactreceiving cavity extending through said block from one of said end sections, through said center section and through the other of said end sections, a first portion of said cavity in said one end section having its axis extending substantially parallel to, and laterally offset from, a third portion of said cavity in said other end section, a second portion of said cavity in said center section extending obliquely with respect to the axes of said first and third portions of said cavity, means to move said end sections relatively towards each other thereby to compress said center section and shorten said second cavity portion whereby, a contact terminal of given dimensions can be inserted through said one end section and at least partially through said center section and into said other end section when said end sections are in their extended positions with respect to each other, and said contact terminal cannot be removed from said cavity after movement of said end sections relatively towards each other with concomitant shortening of said second cavity portion.

2. An electrical connector comprising, insulating block means having hard substantially non-compressible end sections and a soft compressible center section, means for moving said end sections relatively towards each other from an extended position to a proximate position with concomitant compression of said center section, a contactreceiving cavity extending through said block from one of said end sections, through said center section and through the other of said end sections, said cavity having first and third portions in said one end section and said other end section respectively, and said cavity having a second portion in said center section, said second portion extending obliquely with respect to said first and third portions whereby said cavity has a predetermined degree of tortuosity when said end sections are in said extended position, and the degree of tortuosity in said cavity is increased when said end sections are moved towards each other whereby, a contact terminal of given dimensions can be inserted through said one end section and into said other end section when said end sections are in said extended position, and said contact terminal cannot be removed from said cavity when said end sections are in said proximate position.

3. An electrical connector comprising a shell member and insulating block means in said shell, said insulating block means comprising hard end sections and a soft compressible center section, means on said shell for moving said end sections relatively towards each other from an extended position to a proximate position whereby, said center section is compressed and shortened, a plurality of contact-receiving cavities extending through said insulating block means, each of said cavities comprising first and third portions in said end sections and a second portion in said center section, said second portion of each cavity extending obliquely with respect to said first and third portions whereby, each of said cavities has a predetermined degree of tortuosity when said end sections are in said extended position and said degree of tortuosity is increased when said end sections are moved to said proxmiate positions, a contact terminal of given dimensions being insertable through one of said end sections and at least partially through said center section and into said other end section when said end sections are in said extended position, said terminal being retained in said block means when said end sections are in said proximate positions by virtue of said increased degree of tortuosity.

4. A device as set forth in claim 3 wherein one of said sections has ear means extending through said shell, said moving means being engageable with said ear means to move said one section relatively towards said other section.

5. An electrical connector comprising a shell member and insulating block means in said shell, said insulating block means comprising hard end sections and a soft and relatively resilient center section, said center section being in a compressed condition, a plurality of cavities extending through said insulating block means, each of said cavities comprising first and third portions in said end sections and a second portion in said center section, said second portion of each cavity extending obliquely with respect to said first and third portions whereby said cavities are tortuous, contact terminals in at least some of said cavities, each of said contact terminals having at least a major part of its length disposed in one of said end sections, conductors secured to, and extending from said contact terminals, said conductors extending through said center section and through the other one of said end sections,

the degree of tortuosity of said cavities preventing movement of said contact terminals through said center section and said other end section, means efiective between said shell member and said other one of said end sections permitting movement of said other end section away from UNITED STATES PATENTS 2,419,018 4/1947 Gudie 339-217 2,881,406 4/1959 Arson 339-59 MARVIN A. CHAMPION, Primary Examiner.

I. H. MCGLYNN, Assistant Examiner. 

1. AN ELECTRICAL CONNECTOR COMPRISING INSULATING BLOCK MEANS HAVING HARD SUBSTANTIALLY NON-COMPRESSIBLE END SECTIONS AND A SOFT COMPRESSIBLE CENTER SECTION, A CONTACTRECEIVING CAVITY EXTENDING THROUGH SAID BLOCK FROM ONE OF SAID END SECTIONS, THROUGH SAID CENTER SECTION AND THROUGH THE OTHER OF SAID END SECTIONS, A FIRST PORTION OF SAID CAVITY IN SAID ONE END SECTION HAVING ITS AXIS EXTENDING SUBSTANTIALLY PARALLEL TO, AND LATERALLY OFFSET FROM, A THIRD PORTION OF SAID CAVITY IN SAID OTHER END SECTION, A SECOND PORTION OF SAID CAVITY IN SAID CENTER SECTION EXTENDING OBLIQUELY WITH RESPECT TO THE AXES OF SAID FIRST AND THIRD PORTIONS OF SAID CAVITY, MEANS TO MOVE SAID END SECTIONS RELATIVELY TOWARDS EACH OTHER THEREBY TO COMPRESS SAID CENTER SECTION AND SHORTEN SAID SECOND CAVITY PORTION WHEREBY, A CONTACT TERMINAL OF GIVEN DIMENSIONS CAN BE INSERTED THROUGH SAID ONE END SECTION AND AT LEAST PARTIALLY THROUGH SAID CENTER SECTION AND INTO SAID OTHER END SECTION WHEN SAID END SECTIONS ARE IN THEIR EXTENDED POSITIONS WITH RESPECT TO EACH OTHER, AND SAID CONTACT TERMINAL CANNOT BE REMOVED FROM SAID CAVITY AFTER MOVEMENT OF SAID END SECTIONS RELATIVELY TOWARDS EACH OTHER WITH CONCOMITANT SHORTENING OF SAID SECOND CAVITY PORTION. 